The objective of the proposed research is to clarify the relationship between the effects maternal care has on development of reproductive neurobiology and behavior in laboratory rats. This goal will be achieved by concurrent evaluation of the changes in behavior and morphology that result from variation in maternal care. The specific aims of the proposal are: 1. Determine the effects of enhanced maternal stimulation on the development of the spinal nucleus of the bulbocavernosus (SNB), the major pelvic ganglion (MPG), and male reproductive behavior in the laboratory rat. 2. Determine the mechanism(s) by which maternal stimulation affects the morphology of the SNB and the MPG. 3. Determine the effects of deprivation of maternal stimulation on the development of the SNB and the MPG, and male reproductive behavior. These objectives will be archived by using two general models to examine the impact of variation in maternal care on the reproductive well being of males. One model takes advantage of the finding that some mother rats engage in high levels of licking and grooming of their neonatal offspring. This enhanced care facilitates the development of greater reproductive efficacy in the male offspring. The second model is one of maternal neglect and provides the opportunity to study the mechanisms by which severe reductions in maternal care lead to deficits in reproductive function in the male. Both models have parallels in the human where enhanced skin-to-skin contact (Kangaroo Care) accelerates autonomic and neurobehavioral maturation in human infants whereas early physical and emotional neglect in the human increase the risk of disease, and compromises growth and development. Whether it is touching and holding infant humans in a nursery or the maternal stimulation of young animals in a laboratory or animal care facility, the importance of early conspecific contact is of fundamental importance to the health and well-being of the offspring as adults.